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I have a long distance friend who I am trying to help "weld" up an aluminum frame. Same type of thing that we do using a tig machine. Only problem is he doesn't have a welder and is cheap!!! I read some threads on here about brazing aluminum using durafix brazing rods and gave it a try the other day. It worked fine, except it took forever! to heat up the 1x1"x16gauge aluminum square tube that was 2 to 3 feet long. I'm guessing 3 or 4 minutes using a cheap 16oz. propane tank with plumbers torch on the end vs say 10 seconds for tig welding it!I'm sure my vise acted as a huge heat sink, and everyone knows how fast aluminum cools off from just using AL pans in their kitchen, so the 2 to 3 feet of tube length just drew heat out of the brazing zone.So I was thinking if there was a way to insulate the tube that would go a long way in speeding up the process. I was thinking of using 1" thick fiberglass insulation (duct board I have left over from a HVAC project) a few inches from the brazing spot.Maybe someone here has a better solution that is not too expensive to speed up the brazing process?and while I'm asking questions. anyone have a photo of a cheap propane tank gas holder so my arm doesn't feel like it's going go fall after holding up propane tank in air for minutes at a time?Last edited by AluminumWelder; 12-21-2012 at 08:48 AM.
Reply:Since he's cheap tell him how much you paid for your machine and then tell him to buy a thermal arc 186. He should be able to buy the TA 186 for $1600. When brazing you do not melt the parent metal just the filler.
Reply:LOL, dont' think that is in thier budget, he'd rather just wait the extra few minutes each brazed joint!I know you dont' melt the original metal, but you do need to heat it up enough to melt the brazzing rod which is the issue.
Reply:Does he have an o/a setup?
Reply:nope, just plumbers propane torch he got at lowes for $50
Reply:Great way to make a crappy product..If your buddy is too cheap, to invest in the right equipment he really shouldn't be doing the job..Last edited by WeldingMachine; 12-21-2012 at 11:57 AM.Reason: yo mamaBuy American, or don't whine when you end up on the bread line.
Reply:Man, I hope he's not making anything that will carry any load.
Reply:He really needs a better torch. One of the air/propane torches like Goss or turbo torch makes would be a minimum, but they really don't put out enough heat. I'd say an air/acetylene torch would be the minimum or an oxy fuel torch.If he has no other choice but to use the cheap screw on bottles, them he needs to run MAP gas substitute like Bernzomatic Map-Pro. It will burn hotter than propane, but not all screw in torches are designed to use that gas.http://www.homedepot.com/h_d1/N-5yc1...1#.UNSjFqyHPDcSame issue as with tig, you need to get the heat in fast, as the alum will "wick" away the heat because it's such a good heat sink..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:zank and welding machine.....he's making artistic sculpture, no need to call it crappy, some people can't afford to buy a $1600 tig machine that they use to sell inexpensive art work that has no loads. brazing works just fine for this application and is realtively cheap! although slow and annoying to the pros who can tig. DSW thanks for the tips. I'm always surprised how much you know.Last edited by AluminumWelder; 12-21-2012 at 03:14 PM.
Reply:Here's a couple of threads to read - if you haven't searched/found them already.Propane Torch Comparison http://weldingweb.com/vbb/showthread.php?t=48365Aluminum Brazing - Optionshttp://weldingweb.com/vbb/showthread.php?t=46803Rick V 1 Airco Heliwelder 3A/DDR3 CTC 70/90 amp Stick/Tig Inverters in Parallel1 Lincoln MIG PAK 151 Oxy-Acet
Reply:thanks I did search but used the wrong search words. those threads with photos are great.Now where the heck do I find MPS gas??? Is it even made any more?
Reply:Cool. I read frame and I thought something different. I
Reply:Aluminum brazing is plenty strong when done right but there is a pretty steep learning curve to it. It needs to be as clean as if you are tigging it. It's a nice option for when you DON'T want to see a bead. I made a door frame for a equipment rack cabinet to hold smoked plexiglass. When it was done, it looked like it was all one piece like it was extruded but with corners.
Reply:Did you ever visit the Durafix website? They have videos you can view. In the videos they say you only need something like 750 degrees to braze with their rod.
Reply:YES AND thier videos are a bit misleading. they show a brazed 1"thick aluminum plate to a pipe off to the side and quite frankly that is not possible under normal conditions using a plumbers torch. maybe if your pieces are very small and you heat it for 20 minutes.basically 1/16th is about as thick as you can weld and 1/8th if you have short pieces and don't mind being patient.Last edited by AluminumWelder; 12-23-2012 at 01:35 PM.
Reply:my friend went with this set up map pro plus oxygen almost as hot as oxy-acetylene.https://www.youtube.com/watch?NR=1&v...ture=endscreen$60 at lowes and the Map pro gas should last a couple of hours He's going to try an find some oxygen tanks that are much bigger since the supplied one lasts 10 minutes according to video, way too short. might even use a medical oxygen concentrator guess it depnds on how cheap he can get a used one.
Reply:Not sure he's going to have much luck with that as far as changing cylinder sizes. He'd be better off just getting one of the Port-a-torch's from Depot. It will cost more up front, but he'll save n gas in the long run..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:the portatorch uses acetylene and oxygen.the cost of oxygen is the same regardless of system and propane is cheaper than acetyle so I dont' under stand why it would be cheaper with that kit?are you saying that the regulators and nicer torch are worth it in the long run?
Reply:I the only time I did any aluminum brazing was on a crack on a floor scrubber. The crack was about a foot long in a 1/4" thick casting. I V'ed it most of the way through and made 2 passes. It took most of an afternoon and I was using an o/a torch. That was when I decided to get a spool gun. After almost 5 years it has not cracked again. It works but very slow. I would not do it with anything les than a o/a setup.Last edited by osweld; 12-23-2012 at 06:01 PM.Miller XMT 304 cc/cvMiller 12RC w/ 15ft Tweco #4 GunMiller 30A SpoolgunCustom Thermal Arc TA 10/270 Generator "Thermal Star"Smith oxy/acet-propane with weld, cut & rosebud tipsAnd of course grinders, chop saws, hand tools
Reply:Cost of O2 isn't the same regardless of system. The original kit you showed uses disposable cylinders vs refillable ones. One little disposable cylinder costs about $10. I haven't gotten my "tiny" O2 cylinder filled because I never use it, but my 100 CF O2 cylinder costs me about $25 and my 280 cf O2 cylinder costs me $32 to get filled. Those prices are on the high side from what others have posted in the past as well. This has been discussed here several times in the past. Those little disposables are not the "cheap" way to go.You will also probably find that those little propane cylinders aren't inexpensive either, though you can get a setup that will allow you to refill those from a larger 10 or 20 lb cylinder or adapters that will allow larger 20lb cylinders of propane to be used. Be sure to add the cost of the adapters and larger cylinders into your cost equation as well.An air acetylene kit would get hot enough to braze that easily. My LWS sells the inexpensive kits for with a full MC sized Acet cylinder for $140. I picked up 2 different kits off CL with larger B sized Acte cylinders for as cheap as $40 and most run about $75-100.Last edited by DSW; 12-23-2012 at 06:15 PM..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:yeah he;s just probably gonna get a oxygen concentrator used thus no need to buy disposable tanks |
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发表于 2021-8-31 23:39:04